Vaporization Behavior of Chromium Phosphides: The Solid Two‐Phase Regions , , and

Abstract

The vaporization reactions 24/5 normalCrPfalse(normalsfalse)=2/5 Cr12P7false(normalsfalse)+P2false(normalgfalse)false(1194–1479Kfalse) , 2/3 Cr12P7false(normalsfalse)=8/3 Cr3Pfalse(normalsfalse)+P2false(normalgfalse)false(1421–1541Kfalse) , and 2Cr3Pfalse(normalsfalse)=6normalCrfalse(normalsfalse)+P2false(normalgfalse)false(1543–1768Kfalse) have been studied under mass‐loss effusion in the temperature ranges indicated. The reactions are kinetically inhibited. Enthalpies of formation and atomization, respectively, are found to be in kK: for 1/2normalCrPfalse(normalsfalse) , −5.69±0.18 and 49.67±0.2 ; for 1/19 Cr12P7false(normalsfalse) , −4.48±0.32 and 49.47±0.3 ; for 1/4 Cr3Pfalse(normalsfalse) , −3.18±0.04 and 49.08±0.04 . normalCrP is found to follow the trend in atomization enthalpy to valence state atoms established in the series normalMnP , normalFeP , normalCoP , and normalNiP .

Chromium phosphide CrP as highly active and stable electrocatalysts for oxygen electroreduction in alkaline media

“…Chromium phosphide is a hard-wearing metallic conductor displaying a high thermal stability, good resistivity to oxidation and anti-corrosion toward water and dilute acids [22][23][24][25][26][27][28]. These properties make CrP an appealing candidate in a wide range of applications.…”

“…These properties make CrP an appealing candidate in a wide range of applications. However, very few papers have reported the synthesis and applications of chromium phosphides [22][23][24]. In particular, CrP has been produced in film form by chemical vapour deposition [22,23], but never in the form of nanoparticles.…”

Determination of Gibbs free energy of formation of Cr3P by double Knudsen cell mass spectrometry

“…According to the phase diagram in figure 1 [1], intermediate compounds of Cr 3 P, Cr 12 P 7 , CrP, and CrP 2 are reported to exist in this system. However, there are many uncertainties concerning this phase diagram, and thermodynamic properties of these compounds.…”

“…Since the solubility of phosphorus to solid Cr is negligible [1], and Cr 3 P exists as a stable phase, the activities of Cr and Cr 3 P could be set as unity under T = 1643 K. Equation (2) can, therefore, be simplified to…”

“…The two methods are similar and based on vapor pressure measurement generated by decomposing lower phosphides. Myers et al [1] reported the Gibbs free energies of formation of Cr 3 P, Cr 12 P 7 , and CrP determined by a Knudsen effusion technique. Zaitsev et al [2] obtained those of Cr 3 P and Cr 12 P 7 by Knudsen cell mass spectrometry with some metals as reference substances.…”